1. Field of the Invention
The present invention relates to a lamp holder structure for Christmas lamp, and more particularly to a lamp holder structure for three-wire Christmas flashing control lamp, in which when the lamp base of the flashing control lamp is fitted into the lamp holder, three conductive wires of the lamp base are accurately in contact with three metal plates disposed in the lamp holder at correct leg positions.
2. Description of the Prior Art
In general, the Christmas light bulbs are serially connected with each other to form a decorative light string which is suitable to be hung on a tree, a fence, a roof, etc. as a decoration. Typically, the light string includes a flashing control lamp as a control unit for controlling the flickering of the light string.
The conventional lamp holder for the Christmas flashing control lamp includes a lamp holder and a lamp base connected with a flashing control lamp. The flashing control lamp has two conductive wires extending out of the lamp base and positioned opposite to each other at 180 degree intervals. The lamp base is fitted in the lamp holder with the conductive wires in contact with two metal plates disposed in the lamp holder for conducting electricity.
In such lamp base structure, the opposite outer side walls are formed as plane faces and the two conductive wires respectively extend on the plane faces.
The inner wall of the fitting hole of the lamp holder is correspondingly formed with two plane faces on which the two metal plates are disposed. When the lamp base is fitted into the fitting hole of the lamp holder, the two conductive wires are right in contact with the metal plates.
When the above two-wire Christmas flashing control lamp is used to control a light string, the light string can only create a monotonous flashing effect without various flickering patterns. Therefore, it is necessary to provide a three-wire Christmas flashing control lamp which has contact switching function so that the light string can achieve a various flickering effect.
In the three-wire Christmas flashing control lamp structure, it is important to locate the three conductive wires at correct leg positions so as to achieve the expected flickering effect. In case the three conductive wires are incorrectly located, it will be impossible to achieve the flickering function and even a short circuit may take place in the light string circuit. Therefore, when the lamp base is assembled with the lamp holder, the three conductive wires of the flashing control lamp must contact with the three metal plates disposed in the lamp holder at correct leg positions to conduct electricity.